Antibroaching gear or device



July 19, 1949. R, R, NORRIS 2,476,319

ANTIBROACHING GEAR OR DEVICE I Filed Aug. 1, 1945 ROBERT R. NORRIS ado wan Patented July 19, 1949 UNITED STATES PATENT OFFICE ANTIBROACHING GEAR OR DEVICE Robert R. Norris, United States Marine Corps Reserve (Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) 4 Claims.

This invention relates to landing craft adapted for landing equipment and personnel on the beach without the benefit of wharves or docks, and, more particularly it relates to anti-broaching devices for such landing craft.

One type of landin boat now in use is a shallow draft boat capable of being driven far up on a shelving beach and retracted from the beach under its own power. This type of boat is provided with a wide transverse bow which is hinged transversely substantially at the plane of the floor and which may be let down on the shore to form a ramp, serving as a gang plank for the landing of men and equipment. When the ramp is lowered, the terminal edge of the ramp rests on the beach and tends to aid in holding the boat on the beach. In many cases, the holding action of the ramp is entirely inadequate, and the boat may broach or slew around suddenly as a result of the action of wind and waves.

In general, the object of this invention is to provide anchorin means for holding landing craft on the beach in position for unloading.

Another object of the invention is to provide an anti-broaching device which will hold landing craft positively and firmly on the beach without interfering with the landing of personnel and equipment.

A further object of the invention is to facilitate the landing of personnel and equipment by providing an outboard attachment for the terminal edge of bow ramps of landing craft whereby the landin craft is held on the beach without broaching.

Another object of the invention is to provide ramp attachments or devices for landing craft adapted to dig into the beach to hold the craft and restrain it from rearward and sideward movement, and adapted to release when the craft surges forward strongly and then to dig into the beach again at the most forward position.

Other objects and advantages will be apparent from the following detailed description of the invention and from the accompanying drawing, illustrating preferred embodiments of the invention, wherein:

Figure 1 is a perspective view of an illustrative anti-breaching device attached to the terminal edge of the ramp of a landing craft, and

Figure 2 is a detail view in perspective of a spade attachment differing in some respects from the spade attachments shown in Figure 1.

Referring in detail to Figure l, the numeral I denotes a bow ramp of a landing craft in its lowered position. The ramp I0 is of conventional structure and comprises a wide plate, hinged transversely substantially at the plane of the floor of the landing craft, and provided with cables which are secured to the end of the ramp for raising and lowering the ramp, such means (not shown) being well known in the art. The ramp H] is provided at its terminal edge with shaftcarrying means such as bearin blocks II, attached to the ramp I0 by bolts or by welding or other suitable means. The bearing blocks II are provided with bearing sleeves I2 in which shaft I3 is rotatably mounted. Rigidly mounted on the shaft I3 are a plurality of spades I4 or other suitable flukes or pointed elements adapted to dig into the beach when the ramp Ill is lowered.

A tension arm I5 is rigidly secured to the shaft I3, adjacent one end thereof, and extending in the opposite direction to spades I4 and substantially the same plane as said spades. A tension spring I6, one end of which is secured to the end of tension arm I5 and the other end of which is secured to the ramp Ill, holds the tension arm I5 under suitable tension against the vertical position stop I1, and maintains the spades I4 in digging position, substantially vertical to the plane of the ramp I0, until a force is applied which tends to drive the landing craft forward strongly. The shaft I3 rotates through an angle less than depending on the strength of the spring I6, and the spades I4 fold back under the ramp I0, so that they offer slight resistance to the forward movement of the craft.

While only a portion of the structure is shown in Figure 1, it is to be understood that the aforesaid structure may extend over substantially the entire width of the end of the ramp, or duplicate structures may be provided adjacent to the corners of the ramp, leaving an intervening space between two anti-broaching devices. The spades I4 are spaced so that the restraining force is substantially the same with respect to the center line of the boat.

Referring to the modification of the spade shown in Figure 2, the numeral I8 represents a sleeve for mounting the spade I 4 on shaft I3 by suitable means such as by means of a pin, a bolt or by welding. The sleeve I8 is integral with a shank I9 and the body of the spade I4. A reeniorcin member 20 is provided on each side of the spade I4 to give additional strength.

In operation, the vessel can be driven under its own power up on a shelving beach to a point at which it will rest in a stable manner free from rolling. Ramp -I 0 is then lowered, and the spades I4 dig into the sand of the beach, anchoring the craft so that it cannot gain sternway. A forward surge of the craft causes spades M to rotate to an acute angle and pull out of the sand. As soon as the surge is completed, tension spring it pulls the spades to a 90 position, and they again dig into the sandiand anchor the-craft. As the ramp is lifted to close'the how; the spades M are pulled out of the sand on a line with the radius of the arc defining the path of the end of the ramp, rotating on its hinged axis.

While I have illustrated anddescribed'the preferred embodiments of my invention, many modifications and variations of the invention as hereinbefore disclosed may be made without departing from the spirit and scope thereof, and therefore no limitations should be imposedexcept :as are indicated in the appended claims.

The invention described heriein may be manufactured and used by or for the Government of the United States of America for governmental tween saidanchoring'means and said support r .;-means limiting'the movement of said anchoring means.

-2. Ananti-broachingfievi'oe fora landing craft with a bow ramp, comprising anchoring means adjacent the end of-the b'ow ramp, stop means gicr maintaining .said anchoring'means substantially'at-right angles itoth'esplane of said ramp,

to prevent the craft from gaining sternw-ay, and spring means permitting the release of said anchoring means when the craft surges forward.

3. An anti-breaching device for a landing craft with a :bow ramp, comprising a transverse shaft rotatably-mounted adjacent the end tor the bow ramppanchoring means fixed on 'said'shaft to limit said anchoring means to :a position substantially perpendicular to the plane of said ramp when the craft attempts to gain sternway, and s'pring means adapted to permit the release of said anchoring :means when the craft attempts .to 'gain headway.

4. An anti-breaching device for a landin craft with abow-ramn comprising a transverse shaft rotatably mounted adjacent the end of the bow ramp,sp'ade-like anchoring means fixed on said shaftwlimiting smeans adjacent the side of said -r a-mp lebmprism'g' a stop mounted on said ramp and an arm mounted on said shaft, said arm abutting said stop when said spades are'substantially iperpendicularcto s-aidwramp, and :tension spring meansconneoting said armand' said'ramp, permitting :the release ofwsaid anchoring means when the craft surges forward.

ROBERT R. NORRIS.

.REFERENQES LGIiIlED The following referen oesare'of record in the 'file' of this patent:

" UNITED "STATES PATENTS Number Name Date 135,922 Lang Feb. 18, 1873 611,636 'Lake-. :Oct. 4, 1-898 -r1,2-2'1,'156 Dotson-- Apr. 3, 191

"2 341;?366 ZHiggins Feb. '15, 1944 

